Formula within automation

[Ines_Gonzalez_D]

Hi - I am trying to update a forecast in case the field hasn't been updated for over a month. The idea is that if there are no updates, the forecast would lower by 10%. 

It all looks great, until I have to "Update record", I pull the record ID (dynamic) and added the field "Forecasted" and also make it dynamic. I add the field "Forecasted" and multiply it by 0.9. However, this creates an error. Here are the different versions and the results: 

1. "Forecasted"*0.9 --> Error
2. "Forecasted"(0.90) --> Error
3. "Forecasted".9 --> If the original value was $15,000 it shows $150,001 (maybe it thinks I want to move the decimal place?)
4. "Forecasted""Multiply by" --> I created the field "Multiply by" to all equal 0.9 in the data, but whenever I place both of them together, no changes
5. "Forecasted"*"Multiply by" --> Error
6. "Forecasted"10% --> Error

This should be simple, the formula is pretty easy, but for some reason I can't get it to work. Can someone please help me? 

Thanks!

[TheTimeSavingCo · Accepted solution]

I would try:
1. Make "Forecasted" a number/currency field, whichever works for your use case
2. Create a formula field called "Forecasted * 0.9" and give it a formula of `{Forecasted} * 0.9`
3. In the automation, use an Update Record action to paste the value from {Forecasted * 0.9} into {Forecasted}

[Ines_Gonzalez_D]

Thank you! And since this automation should run based on last modified, I am assuming that it will update as necessary. 

Thanks for the help 🙂